1. Field of the Invention
The present invention relates to a circuit board and a liquid crystal display comprising the same. More particularly, the present invention relates to a circuit board that stores externally provided Extended Display Identification Data (EDID) information and a liquid crystal display comprising the same.
2. Description of the Related Art
A liquid crystal display comprises a liquid crystal panel. The liquid crystal panel comprises a first plate comprising a pixel electrode, a second plate comprising a common electrode, and liquid crystal molecules with dielectric anisotropy that are injected between the first plate and the second plate.
By forming an electric field between the pixel electrode and the common electrode, controlling the intensity of the electric field, and controlling the amount of light penetrating the liquid crystal panel, a desired image is displayed. Here, since the liquid crystal display is not a self-luminating display device, a backlight unit operating as a light source is installed in the back of the liquid crystal panel.
In order to drive the liquid crystal display, all of the following components need to be electrically connected: the liquid crystal panel, a plurality of driving ICs to provide signals required to display images, the backlight unit, an inverter, a voltage supplier to provide source voltages, and a plurality of transmit cables to transmit video and audio signals from the external devices.
For the electrical connections, LVDS (Low Voltage Differential Signaling) has been widely used as an internal interface standard. For the external interface standard, VGA (Video Graphics Array) and DVI (Digital Video/Visual Interactive) have been widely used.
In the conventional interface standard of LVDS or DVI, Extended Display Identification Data (EDID) information is stored in a scaler board. Here, EDID information comprises display resolutions of a monitor, horizontal frequency, vertical frequency, a manufacture identifier, a model identifier, and a serial number.
Recently, a new standard that implements a simplified electrical connection with more colors, higher resolution, and a faster refresh ratio is under investigation by the VESA (Video Electronics Standards Association), which establishes standards about displays. As one of the new standard candidates, a digital display interface called “DisplayPort” has received significant attention.
DisplayPort is an interface that can transmit high quality video and audio signals and is capable of a maximum transmission speed of 10.8 Gbps with one cable. Also, an optional functionality to protect transmitted content can be used. As previously stated, EDID information can be stored in a scaler board in the conventional interface standard. But, since the scaler board is removed in the DisplayPort interface, a new structure is required to store EDID information.